The project aims to further develop a novel and highly innovative technology for gene expression profiling. The technology is based on arrays of beads assembled in the ends of fiber optic bundles. The individual beads carry nucleic acid probes. The arrays can attain extremely high packing densities, approximately 1,000 times that of conventional microarrays, and therefore have very high information content. This proposal's specific aims relate to scaling up the technology developed during Phase I into a practical, cost- effective tool for measuring RNA transcript levels. The aims are to increase very substantially the number of unique probes that can be represented on a randomly addressed fiber optic microarray; to use this capacity to develop arrays for comprehensive analysis of gene expression in mouse; and to test the array system side-by-side with conventional array technology. The highly miniaturized, high-capacity arrays are expected to be a cost-effective tool for expression analysis of the mouse genome. The methods and technology will be applicable to the rapid development of arrays for gene expression analysis of other organisms. PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE